Jaegwon Kim has recently argued that the widespread assumption of the multiple realizability of higher-level kinds -- and in particular, psychological kinds -- conflicts with some fundamental constraints on both materialistic metaphysics and scientific taxonomy. Kim concludes that the multiple realizability of psychological kinds would leave them "disqualified as proper scientific kinds" (Kim 1992: 18), and that search for a scientific psychology should focus instead on more reductive or type- materialist possibilities. If correct, this would strikingly undermine a widespread assumption in the philosophy of mind and cognitive science. But it's not.